Spring and slat assembly

ABSTRACT

A metal slat for use in the bottom frame of a box spring has a plurality of slots formed therein. Each slot is defined by a recess having a surface inclined to the upper surface of the slat and a lip. The lowest convolution of a coil spring or the bight of a saddle spring is forced into the slot. The inclined surface of the recess prevents the spring from moving out of the slot once received.

United States Patent 1191 Ciampa et al.

[ SPRING AND SLAT ASSEMBLY [75] Inventors: Fred A. Ciampa; Angelo Serafini,

both of E. Boston; Louis Mazzarella, Boston, all of Mass.

[73] Assignee: Standard Box Spring Company, East Boston, Mass.

22 Filed: Aug. 6, 1973 211 Appl. No.: 386,051

[52] US. Cl 267/100, 5/248, 5/263 [51] Int. Cl A47c 23/02, A47c 23/04 [58] Field of Search 5/256, 263, 264, 265, 351, 5/210, 247, 248, 269; 297/456, 102;

[56] References Cited UNITED STATES PATENTS 197,405, 11/1877 Read 5/264 B 1,299,890 4/1919 Young 267/100 Primary ExaminerCasmir A. Nunberg Attorney, Agent, or Firm-William L. Ericson [57] ABSTRACT A metal slat for use in the bottom frame of a box spring has a plurality of slots formed therein. Each slot is defined by a recess having a surface inclined to the upper surface of the slat and a lip. The lowest convolution of a coil spring or the bight of a saddle spring is forced into the slot. The inclined surface of the recess prevents the spring from moving out of the slot once received.

8 Claims, 14 Drawing Figures SHEU 2 OF 3 SPRING AND SLAT ASSEMBLY Box springs, such as used in the furniture industry, generally comprise a bottom frame having longitudinal beams and transverse slats, a top mat, and compression springs. The compression springs are secured at one end to the traverse slats and at the other end to the mat.

One method employed to secure compression springs, either coil springs or saddle springs, to a slat is to nail the spring to the slat at spaced intervals. The slat may be marked where the spring is to be nailed and the spring manually held in place and nailed to the slat.

Saddle springs may be secured to the slats of a frame by forming bights in the transverse bottom leg of the saddle spring. A disc is received in and engages the bight. The disc is nailed to the slat. This method of securing saddle springs to the slats is described in U.S. Pat. No. 3,681,794, issued Aug. 8, 1972.

Another method employed to secure the coil springs to the slats is-to pass the lowest convolution of a coil spring through apertures in the slats (see for example U.S. Pat. No. 2,841,209, issued July 1, l958; U.S. Pat. No. 2,054,868, issued Sept. 22, l936; and U.S. Pat. No. 2,096,435, issued Oct. 19, 1937). In some embodiments a traverse wire is woven through the engaged convolution and the slat to provide stability to the spring coil. This general method of assembly is timeconsuming, and does not satisfactorily lend itself to automation.

This invention concerns an improved slat to receive and securely hold compression springs and the method of assembling the same. The invention, in its preferred embodiment,includes a channel-like slat having a plurality of slots formed in the upper surface. Each slat is defined by a lip and a recess. The recess extends downwardly from and terminates below the upper surface of the slat; and further, at least a portion of the recess lies in a plane which is inclined to the plane of the upper surface of the slat. This inclination may form any angle with the upper surface, whether acute, right, or obtuse.

To secure a coil spring to the slat, the lowest convolutions are deflected to avoid interfering contact with the inclined surface, and are inserted in the slot. After insertion, the coil is restored to its normal undeflected form and will remain secured in the slot. The inclined surface of the recess will interfere with or prevent its movement out of the slot. No additional structure is required to hold the coil securely to the slat.

To secure a saddle spring to the slat, a bight formed with reverse U-bends is inserted into the slot while the bight is deflected. After the bight has been inserted, it is released to its undeflected form. The inclined surface of the recess interferes with or prevents the movement of the bight ou of the slot.

For saddle springs which have forward bights, such as shown in U.S. Pat. No. 3,68 l ,794, a second slot spaced apart from the first slot is formed in the slat. The bight is inserted into both the first and second slots.

Another aspect of the invention provides a tubular slat having at least two apertures on either side. The end of the lowest convolution of a coil spring is threaded through all four apertures, such as by a twisting motion.

The slats of the present invention with the preformed slots eliminate the necessity of separately marking the slat to locate the position where the spring is to be secured. The slots function as a jig to locate the springs at the proper locations along the slat. Further, the slat allows the securing of the springs to the slat to be automated.

Whether a tubular slat or channel-like slat is used, the ends of the slat may be flattened and formed into claws, which claws may be driven into the longitudinal beams of the bottom frame.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of one embodiment of the invention, showing coil springs secured to slats in a bottom frame;

FIG. 2 is a side partially sectional view of a coil spring and a slat of FIG. 1;

FIG. 3 is an end view of the slat of FIG. 2, taken along lines 3-3 of FIG. 2;

FIG. 4 is a plan view of FIG. 2;

FIG. 5 is a partial plan view of the end of a slat secured to the bottom frame;

FIG. 6 is a front partially sectional view ofa claw-like end of a slat received in the bottom frame;

FIG. 7 is an end view of FIG. 6, less the bottom frame;

FIG. 8 is an isometric view ofa saddle spring secured to a slat;

FIG. 9 is an end, partially sectional view of FIG. 8, taken along line 9-9 of FIG. 8;

FIG. 10 is a side, partially sectional view of FIG. 8, taken along line 10-10 of FIG. 8;

FIG. 11 is an isometric view of a multiple-slat saddle spring secured to two slats;

FIG. 12 is an isometric view of a half saddle spring secured to a slat;

FIG. 13 is an isometric view of a half saddle spring secured to a multi-slotted slat;

FIG. 14 is a side, partially sectional view of the saddle spring and slat of FIG. 13;

FIG. 15 is a side partially sectional view of a coil spring secured to a tubular slat having claw-like ends; and

FIG. 16 is a top plan view of the slat and end of FIG. 16.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, a plurality of channel-like transverse slats 14 embodying the preferred embodiment of the invention are fastened to longitudinal beams 12. Spring coils 16 are secured to the slats 14 in spaced relationship.

As shown in FIGS. 2, 3 and 4, the slat 14 includes recesses 17 extending downwardly and terminating below and spaced apart from the upper surface; and lips 19, lying in the plane of the upper surface of the slat. Each recess includes a surface 21 inclined to the plane of the upper surface. The recesses 17 and the lips 19 define the slots 18. To insert the coil 16 into the slot, the lowest convolutions 20 and 22 of the coil are deflected and the lowest convolution 20 inserted into the slot. This deflection is achieved by forcing the spring to enter the slot until it reaches the illustrated position. After insertion the coil is elastically restored to its undeflected form. The inclined surface 21 prevents the coil, when the lower convolutions are in normal undeflected form, from moving out of the slot 18. If it becomes necessary to remove the coil spring 16 because of some discovered defect, the lower convolutions 20 and 22 must be deflected with a screwdriver or other tool to avoid interfering contact with the inclined surface 21, before the coil can be removed from the slot.

As shown most clearly in FIG. 3, the slat 14 includes side walls 23 and stiffening flanges 24.

The ends of the slats 14 may be formed in various ways in order to secure them to the traverse beams 12. In FIG. 5, the end of the slat 14 is flattened at 26 and is secured to the beam 12 by nails 28. In FIG. 6, the slat 14 has been flattened at 30 and shaped into claws 32, which are driven into the beam 12. FIG. 7 is an end view of FIG. 6 without the beam 12, illustrating a preferred shape of the claws 32.

In FIGS. 8, 9, and 10, a saddle spring 40 is secured to a channel-like slat 38. The saddle spring 40 includes parallel bottom legs 42, and upwardly and inwardly sloping side legs 46 connected to the bottom legs by curved portions 44. Transverse top legs 50 are connected to the side legs 46 by curved portions 48. Legs 49 a and b, parallel to the top legs 50, are secured to the bottom legs 42 by curved portions 51. Reverse bights or convolutions 52 a and b are secured to the legs 49a and b by reverse U-shaped bends 54a and b. As shown most clearly in FIG. 10, the slat 38 includes two recesses 55a and b which extend downwardly from the upper surface of the slatin opposite directions and terminate below the plane of the upper surface and spaced apart therefrom. The recesses 55a and b include surfaces 59a and b which are inclined to the plane of the upper surface of the slat 38. Lips 57a and b lying in the plane of the upper surface define, with the recesses 55a and b, slots 56a and b. To secure the spring 40 to the slat 38, the bights 52a and b are deflected to avoid interfering contact with the inclined surfaces 59a and b and inserted in the slots 56a and b. After insertion into the slots 56a and b, the bights 52a and b are released to undeflected form. The inclined surfaces 59a and b prevent the movement of the bights 52a and b out of the slots 56a and b.

In FIG. 11, a multiple-slat saddle spring 60 is secured to two adjacent slats 38. Bights 62a, b, c, and d are received in slots 64a, b, c, and d in the manner as described for the slat and saddle spring combination of FIGS. 8, 9, and 10.

A half saddle spring 64 is shown in FIG. 12 and includes two parallel bottom legs 66, two upwardly and forwardly directed parallel side legs 68 secured to the bottom legs 66 by curved portions. A top leg 70 transverse to the bottom legs 66 is secured to the side legs 68 by curved portions 69. The outer sides of reverse bights 73a and b are secured to the bottom legs 66 by reverse U-shaped portions 71. The inner sides of the bights 73a and b are secured to parallel legs 72, which legs are parallel to the bottom legs 66, by reverse U- shaped portions 71. Transverse leg 75 is secured to the legs 72 by the curved portions 74. Slats 76a and b include slots 78a and b dimensioned as described for the prior embodiments. The bights 73a and b are received in slots 78a and b.

A slat 82, FIGS. 13 and 14, includes a first slot 84, dimensioned as described for the prior embodiments. A recess 86 is formed in the slat 82 and lies in a plane substantially below the plane of the upper surface of the slat 82. The recess 86 in combination with the slat 82 defines a slot 88, most clearly shown in FIG. 14. A

half saddle spring 80, which includes a forward bight 81, is received in both the slots 84 and 88.

The inclined surface of the recess which prevents the movement of the compression spring out of the slot once inserted has been shown and described in FIGS. 1-14 as lying in a plane which is at an acute angle to the plane of the upper surface of the slat. The inclined surface may be at any angle, acute, right or obtuse, to insure that once a spring is inserted into the slot and is in normal undefiected form, the indexed surface will interfere with its removal from the slot. Any structure which will accomplish this junction may be employed. For example, rather than form the inclined surface from the upper surface of the slat, a separate piece could be secured to the lower surface of the slat to provide the inclined surface.

Having described the invention, what is now claimed 1. A slat-spring assembly which comprises:

at least one compression spring having a lower convolution of predetermined height and width;

a slat having an upper surface and a parallel lower surface, said slat being formed with a recess portion and a lip portion defining a slot therebetween, said recess portion extending downwardly from said upper surface and terminating below said' lower surface and being spaced apart therefrom, at least a portion of the surface of said recess portion which adjoins said upper surface being inclined thereto;

said slot having a cross-sectional height and width sufficient to receive said lower convolution of said spring by a translatory movement thereof accompanied by elastic deformation of said lower convolution, said inclined surface portion interfering with removal of said lower convolution in a relaxed, undistorted condition from said slot.

2. The assembly of claim 1, wherein said compression spring is a coil spring having a plurality of convolutions, and the lowest convolution of said coil spring is inserted into said slot into contact with said lower surface of said slat and said recess portion, and the next lowest convolution of said coil spring contacts said upper surface of said slat.

3. The assembly f0 claim 1, wherein said compression spring comprises a saddle spring having a lower convolution comprising a bight formed on a bottom transverse leg thereof, and said bight is received in said slot.

4. The assembly of claim 3, said slat including a sec ond recess portion and a second lip portion formed in said slat and defining a second slot therebetween, said second recess portion extending downwardly from said upper surface and terminating below said lower surface in spaced-apart relation thereto, at least a portion of the surface of said recess portion which adjoins said upper surface being inclined thereto;

said saddle spring including lower convolutions comprising first and second bights ofpredetermined height and width, said slots having crosssectional heights and widths sufficient to receive said bights of said spring by translatory movements thereof accompanied by elastic deformation thereof, said inclined surface portions of said first and second recess portions interfering with removal of said bights in a relaxed, undistorted condition from said slots.

6 said slots.

7. The assembly of claim 1, wherein the ends of said slat are flattened.

8. The assembly of claim 7, wherein said flattened ends are formed with claw portions extending at an angle to the length of said slat. 

1. A slat-spring assembly which comprises: at least one compression spring having a lower convolution of predetermined height and width; a slat having an upper surface and a parallel lower surface, said slat being formed with a recess portion and a lip portion defining a slot therebetween, said recess portion extending downwardly from said upper surface and terminating below said lower surface and being spaced apart therefrom, at least a portion of the surface of said recess portion which adjoins said upper surface being inclined thereto; said slot having a cross-sectional height and width sufficient to receive said lower convolution of said spring by a translatory movement thereof accompanied by elastic deformation of said lower convolution, said inclined surface portion interfering with removal of said lower convolution in a relaxed, undistorted condition from said slot.
 2. The assembly of claim 1, wherein said compression spring is a coil spring having a plurality of convolutions, and the lowest convolution of said coil spring is inserted into said slot into contact with said lower surface of said slat and said recess portion, and the next lowest convolution of said coil spring contacts said upper surface of said slat.
 3. The assembly fo claim 1, wherein said compression spring comprises a saddle spring having a lower convolution comprising a bight formed on a bottom transverse leg thereof, and said bight is received in said slot.
 4. The assembly of claim 3, said slat including a second recess portion and a second lip portion formed in said slat and defining a second slot therebetween, said second recess portion extending downwardly from said upper surface and terminating below said lower surface in spaced-apart relation thereto, at least a portion of the surface of said recess portion which adjoins said upper surface being inclined thereto; said saddle spring including lower convolutions comprising first and second bights of predetermined height and width, said slots having crosssectional heights and widths sufficient to receive said bights of said spring by translatory movements thereof accompanied by elastic deformation thereof, said inclined surface portions of said first and second recess portions interfering with removal of said bights in a relaxed, undistorted condition from said slots.
 5. The assembly of claim 4, said second recess extending in a direction opposite the direction in which said recess of said first slot extends.
 6. The assembly of claim 3, said slat including a second recess portion spaced apart from said first recess portion, said second recess portion extending below said lower surface and defining a second slot therewith, said bight of said saddle spring being received in both said slots.
 7. The assembly of claim 1, wherein the ends of said slat are flattened.
 8. The assembly of claim 7, wherein said flattened ends are formed with claw portions extending at an angle to the length of said slat. 